1 Reply Latest reply: Jul 9, 2010 8:11 AM by Aaron Sheffey RSS

JBoss 4.2.3, mod_jk, and intermittent performance

Aaron Sheffey Newbie

We have web apps deployed with a typical Apache 2, mod_jk 1.2.*, JBoss 4.2.3 infrastructure.  I've been trying to diagnose an ongoing issue with an application deployed on this stack.

 

Level set:

 

  • The Java application is not slow.  Controller times are generally in the 5-500 ms range.
  • Requests through the Apache front-end show intermittent latency; on one request, the entire round-trip takes less than a second.  The next click, it takes up to 30.  And then back to less than a second.
  • If you directly access the Java application via the JBoss URL (e.g., http://10.1.1.1:8080/foo/),  there is only DB latency, (except for JS, Images, and CSS calls because they use the Apache URL), with some intermittent network  latency.
  • If you run the Java  application locally, there is only DB latency.

 

This behavior is consistent across all of our JBoss 4.2.3 web applications.  On the other hand, we also have applications  deployed on JBoss 4.0.2 with the same Apache and mod_jk front-end, and they do not exhibit this behavior – Apache to JBoss roundtrip latency is small to nil.

 

So, what is different?  I’ve been researching JBoss 4.2.3 today, and there are some issues with the newer version of embedded Tomcat in terms of CLOSE_WAITs.  I’ve put in place the needed config to account for that issue.  However, the latency issue  remains.

 

I'm pulling my hair out on this one...any help would be most appreciated.  Thanks!

 

Aaron